Tesseract OCR
Open-source OCR engine and command-line tool, with no graphical interface.
Jobs OCR
Since 2005
Where your files are processed
Mixed — depends on version and feature
The vendor's own documentation separates them. On the device: The Tesseract engine installed locally. On their servers: A hosted integration a developer builds around it. A single answer for the whole product would be wrong for one of them. That is a property of the library itself: what an application built with it does with your file depends on that application, not on this.
It is a locally installed engine, so it runs where it is installed and processes what it is given. Where that happens depends on how a developer deploys it: an embedded library or a command-line call keeps the file on the machine, while a third-party hosted integration can receive files, which is a property of that service rather than of Tesseract. It also does not read PDFs, so a PDF workflow has to rasterise pages first.
What it does
Tesseract is a text-recognition engine that pulls printed text out of images and scanned pages. It ships as a command-line program plus a C and C++ library that other applications embed, and it has no interface of its own. It reads PNG, JPEG and TIFF and writes plain text, hOCR, TSV, ALTO, PAGE, or a searchable PDF with an invisible text layer. It can be retrained for additional languages and scripts.
Best for: Developers and technical users who need scriptable, fully offline OCR inside their own pipeline, and who will pair it with a separate interface or wrapper.
Worth knowing: There is no built-in graphical interface — the project says so explicitly. Accuracy depends heavily on image quality and usually needs preprocessing, and the project's own FAQ confirms it cannot read handwriting or barcodes.
Details, and where each comes from
Vendor statements, our own reading of their pages, and the things nobody has established yet, each answered separately. Where we have not confirmed something it says so rather than guessing, and a row nobody has established is greyed out.
- Versions covered
- Windows · macOS · Linux
- Website
- tesseract-ocr.github.io
- Requires an account
- Not applicable
- Watermark on the free tier
- No
- Maximum file size
- Not verified
- Batch processing
- Yes
- Data residency
- Self-hosted
- Open source
- Yes
- Self-hostable
- Yes
- Licence
- Apache-2.0
- Redaction
- No redaction feature
- Programmatic access
- Embeddable library · Command line
- Last availability check
- Responded in 72 ms 16 October 2026
Checked automatically by our own runner, not reported by the vendor. 100% of our last 30 checks got a response.
What the redaction verdict rests on
From the vendor's own documentation, read 22 September 2026. Not tested by us.
What that does not establish: The repository README is the source, because the project site renders from JavaScript. Tesseract is an OCR engine: it extracts text from images and has no feature that alters a PDF’s content. The vendor’s own published material was read on 22 September 2026 and contains no mention of redaction, sanitisation, blackout or whiteout. Absence from a vendor’s own material is not proof that a feature does not exist — it may be undocumented, or on a page the reading did not reach — but for a NEGATIVE claim it is the strongest evidence available, and it is weaker than a positive quote. Recorded as such rather than presented as certainty.
What the vendor says
Claims are labelled rather than repeated as fact. Where we have checked something ourselves, it says so and shows when. Checked means we read the vendor's own page and it says what we recorded — not that we tested the behaviour, unless the note says we did.
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“Tesseract has unicode (UTF-8) support, and can recognize more than 100 languages out of the box”
Checked by us — the source says this Read 22 September 2026
Confirmed verbatim: the sentence appears unaltered in the README, and the phrase "out of the box" is the vendor's own, quoted here as written. It is a countable capability claim — more than 100 languages — and the language data is what makes it true or not, so this is one of the few claims in the tier that a reader could test in an afternoon by running the engine against a document in an uncommon language. Nothing was installed, and the count was not checked against the language data files. Two downstream entries in this index, Tesseract.js and gImageReader, both describe themselves in relation to this project rather than claiming recognition of their own.
Standing: Re-read and matched byte for byte
Check it yourself: the source, the SHA-256, and how we checked
- From
- the text a browser renders
- SHA-256
- d6779f1b57ba7055dbb3c17a43625cdfee23d7133a73b41c6ab17bc30a562b5e
How we checked: Re-verified verbatim on 2026-09-22: https://github.com/tesseract-ocr/tesseract re-rendered in headless Chrome with scripts/render-page.mjs and the claim's wording found in the rendered text. Originally verified on 2026-09-21. sourceHash is the SHA-256 of the re-rendered text, held as rv-github-com-tesseract-ocr-tesseract-9484da05.txt.
Each claim is quoted from the vendor's own pages. This section describes what we have and have not checked — it is not a judgement about anyone.
Sponsorship is distribution, not an endorsement or a promise of search rankings, AI citations, traffic, or sales. This listing is a free entry, compiled from published sources.
Related reading
- Open source PDF tools, and what their licences require — what open source does and does not tell you.
Compared head to head
- Tesseract OCR vs OCRmyPDF The OCR engine, and the tool built on top of it.